docs: async def post(self, cmd, data=None, timeout=None, **args):
          """Perform DAAP POST command with optional data."""
          def _post_request():
              headers = copy(_DMAP_HEADERS)
              headers['Content-Type'] = 'application/x-www-form-urlencoded'
              return self.http.post_data(
                  self._mkurl(cmd, *args),
                  data=data,
                  headers=headers,
                  timeout=timeout)
  
          await self._assure_logged_in()
          return await self._do(_post_request)